In textile yarn processing machines, such as two-for-one twisters, yarn is pulled from a hollow supply package carried by a stationary carrier mechanism in each of a plurality of spindle assemblies and passed through the hollow center of each yarn package by passing through a yarn passageway in the stationary carrier mechanism and a joining yarn passageway in a rotor mechanism and then radially out of the rotor mechanism for further travel through each spindle assembly in a well known manner for processing of the yarn, such as the insertion of a two-for-one twist therein.
Originally, threading of the yarn through such passageways in the carrier mechanism and the rotor mechanism of spindle assemblies of such textile yarn processing machines was accomplished manually. This manual threading operation was extremely time consuming and cumbersome and reduced the efficiency of the machine operation.
Pneumatically operated threading mechanisms have been proposed for such yarn processing machines, as disclosed in U.S. Pat. No. 3,731,478, issued May 8, 1973, and assigned to the assignee of the present invention. In the pneumatically operated threading mechanisms of this prior U.S. patent, an aspirating or ejector nozzle was provided in the rotating rotor mechanism of the spindle assembly which received air under pressure from a coupling or connecting member.
In one embodiment illustrated in the aforementioned U.S. Pat. No. 3,731,478, the coupling or connecting member, which was non-rotating, had to be coupled or connected with a non-axially positioned aperture in the bottom of the rotating rotor mechanism which required positioning of the rotor mechanism when stopped for threading-up of the spindle assembly in a predetermined position for effecting such coupling connection. Accordingly, if the rotor mechanism stopped in a position other than the predetermined position, the rotor mechanism had to be repositioned for effecting the aforesaid coupling for operating the threading mechanisms.
In another embodiment of the aforesaid U.S. Pat. No. 3,731,478, stopping of the rotor mechanism in a predetermined position for alignment with the coupling or connecting member for operating the threading mechanisms was eliminated by disposing the coupling or connecting member axially through the rotor mechanism or whorl portion thereof for alignment with an axially positioned aperture or port in the yarn storage or reserve disc of the rotor mechanism. However, even with this arrangement, coupling was required between a stationary coupling or connecting member and the rotary yarn reserve disc of the rotor mechanism which presented problems in maintenance and proper operation of the pneumatic threading mechanisms.
More recently, pneumatically operated yarn threading mechanisms have been proposed for such yarn processing machines, as disclosed in U.S. Pat. No. 3,975,893, issued Aug. 24, 1976, and assigned to the assignee of the present invention, which eliminated the above problems presented with prior pneumatically operated threading mechanisms and specifically eliminated the necessity of predetermined positioning of the rotor mechanism for the threading operation by rendering the threading mechanisms independent of the position of the spindle assembly rotor mechanism.
In the threading mechanisms in accordance with this U.S. Pat. No. 3,975,893, a selectively-operated air injector nozzle means was positioned at the juncture of the respective yarn passageways through the stationary carrier mechanism and the rotating rotor mechanism for creating an air suction through the carrier mechanism passageway and a jet of positive air flow through the rotor mechanism passageway. Means were provided for selectively supplying air under pressure to the injector nozzle means which included an air duct extending through the stationary carrier mechanism from the air injector nozzle means to an outer end and an air supply connector member mounted for placement into and out of connecting engagement with the outer end of the air duct.
The specific embodiment described and illustrated in the aforesaid U.S. Pat. No. 3,975,893 provided for the air duct means leading from the outer circumference of the bottom portion of the stationary carrier mechanism, radially through such bottom portion and then axially up through the hub portion of the stationary carrier mechanism to the air injector nozzle means. With the air duct arranged in this manner, the bottom portion of the carrier mechanism must be of a sufficient thickness to be capable of accommodating the air duct. This presented problems with respect to construction of the carrier mechanism and resulted in undue bulk in the bottom portion of such carrier mechanism.
Accordingly, it is the object of this invention to obtain the benefits and advantages of the pneumatically operated yarn threading mechanisms of assignee's prior U.S. Pat. No. 3,975,893 over previously proposed devices and methods for threading spindle assemblies of such textile yarn processing machines, while overcoming the disadvantages and problems presented with the threading mechanisms of U.S. Pat. No. 3,975,893 and eliminating the necessity for having a bottom portion of the carrier mechanism in spindle assemblies for such textile yarn processing machines of a thickness sufficient to accommodate an air duct.